Effect of Arbuscular Mycorrhizal Fungal Inoculation on Sorghum bicolor Growth at Different Phosphate Levels: A Greenhouse Study

In sub-Saharan Africa, Sorghum (Sorghum bicolor) is an important cereal for both human being and animals. Unfortunately, its production is confronted to soils with deficiency of phosphorus. Traditional use of mineral phosphate on this culture fertilization is expensive and may cause contamination. It is thus necessary to seek more efficient and economic reasonable techniques to improve sorghum growth. Arbuscular mycorrhizal fungi (AMF) constitute a reference for phosphorus improvement and plant nutrition. This study aimed to investigate the effects of AMF strains (Rhizophagus irregulare, Glomus aggregatum, G. mosseae) on growth of sorghum cultivated in greenhouse on Sangalkam soil (Senegal) sterilized with or without Tilemsi natural phosphate (PNT). The phosphorus can represent until 0.2% of the dry weight of the plant. Two fertilizers were used separately and together to doses of 20 g by strain, 100 mg and 200 mg of PNT. The experiment lasted for 120 d. Results showed that mycorrhizal colonization intensity varied between 40% and 80% for all treatments. AMF inoculation increased sorghum plant height and biomass, regardless of PNT amendment. The inoculation permits to bring strain of AMF that intervene efficiently in the transportation and the availability of phosphorus for the plant.